Since build 5.2.1056 WebRTC Selective Forwarding Unit (SFU) is supported with any tracks count publishing and playing in one WebRTC connection (Simulcast). THis This feature may be used for:

publishing a strem in a number of encodings (for example, 720p, 360p, 180p) with quality switching on the fly
video and audio chat rooms building

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Supported platforms and browsers

	Chrome	Firefox	Safari 11	Chromium Edge
Windows	+	-		+
Mac OS	+	-	+
Android	+	-		+
iOS	+ (iOS 14.4)	-	+

Supported codecs

WebRTC video:

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codecs_exclude_sfu=alaw,ulaw,g729,speex16,g722,mpeg4-generic,telephone-event,flv,mpv,vp8,h265
webrtc_cc_min_bitrate=5000001000000
profiles=42e01f,640028

Note that publishing and playing a number of VP8 streams with a number of encodings requires a client desktop resources. If resources are not enough, H264 should be preferred because a most of browsers support hardware acceleration for H264 encoding/decoding.

Quick testing guide

1. Download latest SFU SDK buildOpen SFU client example in browser, for example 1.0.1.25

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https://demo.flashphoner.com:8888/

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client2/

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sfu/

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2. Unpack build archoive on your server

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cd /usr/local/FlashphonerWebCallServer/client2
mkdir sfu
cd sfu
tar -xzf ~/flashphoner-sfu-sdk-1.0.1.25-f8ea43bab4924798db5fa63b7b609995360e135b.tar.gz

3. Open SFU client example in browser, for example https://test1.flashphoner.com:8444/client2/sfu/examples/client/main.html, enter server URL, room name, pin code and user name, then click Enter

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4. User1 stream is publishing in ROOM1 room

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720p encoding publishing stats

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360p encoding publishing stats

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5. Open example page in other browser or in another browser window, enter server URL and room parameters as on step 3, but change user name to User2

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6. User2 stream is playing in User1 window

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Streams monitoring in the room

Use REST API to monitor streams parameters in the room

REST queries

REST query must be HTTP/HTTPS POST request as follows:

HTTP: http://wcs:8081/rest-api/sfu/stats
HTTPS: https://wcs:8444/rest-api/sfu/stats

Здесь:

wcs - WCS server address
8081 - standard REST / HTTP WCS server port
8444 - standard HTTPS port
rest-api - URL mandatory part
/sfu/stats - REST method used

REST queries and responses

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REST query

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Body example

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Response example

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Response statuses

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Description

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/sfu/stats

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{
 "roomName":"ROOM1"
}

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client/main.html, enter server URL, room name, pin code and user name, then click Enter

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2. User1 stream is publishing in ROOM1 room

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720p encoding publishing stats

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360p encoding publishing stats

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3. Open example page in other browser or in another browser window, enter server URL and room parameters as on step 3, but change user name to User2

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4. User2 stream is playing in User1 window

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Streams monitoring in the room

Use REST API to monitor streams parameters in the room

REST queries

REST query must be HTTP/HTTPS POST request as follows:

HTTP: http://wcs:8081/rest-api/sfu/stats
HTTPS: https://wcs:8444/rest-api/sfu/stats

Здесь:

wcs - WCS server address
8081 - standard REST / HTTP WCS server port
8444 - standard HTTPS port
rest-api - URL mandatory part
/sfu/stats - REST method used

REST queries and responses

REST query

Body example

Response example

Response statuses

Description

/sfu/stats

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{
 "roomName":"ROOM1"
}

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{
  "participants": [
    {
      "nickName": "User1",
      "outgoingTracks": [
        {
          "id": "9de9107c-ce5f-4d6b-b7d6-ea233d691d09",
          "codec": "opus",
          "bitrate": 0,
          "sampleRate": 48000,
          "channels": 2,
          "alive": true,
          "type": "AUDIO"
        },
        {
          "id": "237dcef9-c66d-4c72-bd43-0c91aaea3b7e",
          "composite": true,
          "tracks": {
            "h send": {
              "id": "237dcef9-c66d-4c72-bd43-0c91aaea3b7e",
              "codec": "H264",
              "width": 1280,
              "height": 720,
              "fps": 30,
              "bitrate": 157976,
              "alive": true,
              "type": "VIDEO"
            },
            "m send": {
              "id": "237dcef9-c66d-4c72-bd43-0c91aaea3b7e",
              "codec": "H264",
              "width": 640,
              "height": 360,
              "fps": 30,
              "bitrate": 263952,
              "alive": true,
              "type": "VIDEO"
            }
          }
        }
      ],
      "incomingTracks": {
        "3c2dcd1c-7acd-4b90-8871-331be80cade0": "h send"
      }
    },
    {
      "nickName": "User2",
      "outgoingTracks": [
        {
          "id": "3c2dcd1c-7acd-4b90-8871-331be80cade0",
          "composite": true,
          "tracks": {
            "h send": {
              "id": "3c2dcd1c-7acd-4b90-8871-331be80cade0",
              "codec": "H264",
              "width": 1280,
              "height": 720,
              "fps": 30,
              "bitrate": 238688,
              "alive": true,
              "type": "VIDEO"
            },
            "m send": {
              "id": "3c2dcd1c-7acd-4b90-8871-331be80cade0",
              "codec": "H264",
              "width": 640,
              "height": 360,
              "fps": 30,
              "bitrate": 265368,
              "alive": true,
              "type": "VIDEO"
            }
          }
        }
      ],
      "incomingTracks": {
        "9de9107c-ce5f-4d6b-b7d6-ea233d691d09": null,
        "237dcef9-c66d-4c72-bd43-0c91aaea3b7e": "h send"
      }
    }
  ]
}

200 - OK

404 - Not found

500 - Internal error

Show current room stats

Parameters

Name	Description	Example
roomName	Room name	ROOM1
participants	Participants list	[]
nickName	User name	User1
outgoingTracks	Streams publishing list	[]
incomingTracks	Streams playing list	{}
id	Mediasession id	9de9107c-ce5f-4d6b-b7d6-ea233d691d09
codec	Video or audio codec	H264
width	Video width	1280
heigth	Video height	720
fps	Video FPS	30
bitrate	Video or audio bitrate, bps	265368
sampleRate	Audio sample rate, Hz	48000
channels	Audio channels count	2
alive	Is stream active	true
type	Stream type	VIDEO
composite	Stream includes a set of tracks	true
tracks	Tracks list in composite stream	{}

SFU streams availablility as WCS streams

Since build 5.2.1068 it is possible to bridge SFU streams to WCS as usual WebRTC streams. This feature is enabled by default with the following parameter

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sfu_bridge_enabled=true

In this case, for every participant video stream will be available as{room}-{participant}-VIDEO and audio stream will be available as {room}-{participant}-AUDIO. Those streams are visible in statistics page

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-----Stream Stats-----
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streams_viewers=ROOM1-User1-AUDIO/0;ROOM1-User1-VIDEO/0
streams_synchronization=ROOM1-User1-AUDIO/0;ROOM1-User1-VIDEO/0

may be played from server

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may be recorded by REST API or added to mixer.

When screen is published, it is available as {room}-{participant}-VIDEO-screen, for example

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-----Stream Stats-----
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streams_viewers=ROOM1-User1-AUDIO/0;ROOM1-User1-VIDEO-screen/0;ROOM1-User1-VIDEO/0
streams_synchronization=ROOM1-User1-AUDIO/0;ROOM1-User1-VIDEO-screen/0;ROOM1-User1-VIDEO/0

If SFU stream is published in a number of qualities, it will be available at WCS side as maximum quality stream which is publishing, for example 720p. If this quality is stopped (for example, participant channel becomes worse), WCS stream will be automatically switched to the next available quality, fro example 360p.

Known limits

If participant publishes more than one stream from camera, only the first published stream will be available at WCS side.

TURN support

A standard RTCPeerConnection object is used in browser to publish and play audio and video tracks, so this object should be configured properly to relay a media traffic via TURN server. For example, all the streams are published directly to WCS instance in SFU Two Way Streaming example:

code

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pc = new RTCPeerConnection();
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The code should be changed as follows to use a TURN server, for example, internal WCS TURN server:

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let connectionConfig = {
    iceServers: [
        {
            urls: 'turn:wcs:3478?transport=tcp',
            credential: 'coM77EMrV7Cwhyan',
            username: 'flashphoner'
        }
    ],
    iceTransportPolicy: "relay"
};
pc = new RTCPeerConnection(connectionConfig);
...

Where:

wcs - WCS server address;
flashphoner - WCS internal TURN server default username;
coM77EMrV7Cwhyan - WCS internal TURN server default password

In this case all the media traffic will pass through the WCS internal TURN server. This feature may be also used to wrap WebRTC traffic to TCP if the client has a bad channel, because WCS does not support TCP transport for SFU streams.

Known problems

1. A stream captured from a screen window simulcast publishing will crash Chrome browser tab on minimizing this window

Symptoms: when stream is capturing from active screen window, Chrome tab crashes if this window is minimized by user

Solution: there is the Chromium bug, a stream capturing from a screen window should be publihed in only one quality (no simulcast) until this bug is fixed (in Chrome build 98.0.4736.0)

Space shortcuts

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Versions Compared

Old Version 1

New Version Current

Key

Supported platforms and browsers

Supported codecs

Quick testing guide

Streams monitoring in the room

REST queries

REST queries and responses

Streams monitoring in the room

REST queries

REST queries and responses

Parameters

SFU streams availablility as WCS streams

Known limits

TURN support

Known problems

Space shortcuts

Page tree

Page History

Versions Compared

Old Version 1

New Version Current

Key

Supported platforms and browsers

Supported codecs

Quick testing guide

Streams monitoring in the room

REST queries

REST queries and responses

Streams monitoring in the room

REST queries

REST queries and responses

Parameters

SFU streams availablility as WCS streams

Known limits

TURN support

Known problems